TK hop twist barrels, are they worth it?

[Glenn]

The only way you're really going to figure out if you'd like one is to give it a try.

 

 

This is really what it comes down to.

 

And I've read that Koba Magic thing before...an explanation it is not.

 

I'm pretty sure TK decided rifling would be neat to try, and make a nice selling point. Obviously, he was right, as a barrel with no consistantly agreed upon advantage is still selling.

[Stealthbomber]

I'm pretty sure TK decided rifling would be neat to try, and make a nice selling point.

I must say, I wouldn't be surprised if this was the real reason for it.

 

Airsofters are suckers for realism and the japanese tend to be slightly obsessive too.

The idea of having a barrel with "rifling" in it is almost irresistible. I wouldn't be surprised if the original concept was just to cut the rifling into a tightbore to see what happened and, when it turned out it didn't affect it too much, they came up with the "science part" and stuck it on sale.

[Sale]

Or, in summary, for the TK barrel to increase the range of a gun it must provide some way for the BB to maintain a stable rate of backspin for a longer period.

Possible?

You decide.

In other words, the BB would have to "know" what kind of weapon was used to shoot it, and "remember" it downrange.

 

This is the same argument I've used when people have hyped their LRBs: The BB doesn't have a darn memory! But with LRBs I have thought of a different explanation to the increased range: The bore slopes down, so the BB is initially shot downwards. This allows you to apply more spin to the BB without having it curve up, because the lift first has to overcome the downward motion. In the end the BB has more spin left, so it reaches further. You could replicate this by adjusting the iron sights to shift the POI lower, and increase hop-up to compensate.

 

Maybe that's what it really does...just aplifies the effect of the hop on the bb and that may be why people "seem" to be getting greater distances with the hop-twist.

You should be able to replicate that by increasing hop-up with a regular barrel.

 

I've only ever compared the TK to other barrels in a 5.1 Hi-Capa, and didn't see a significant difference one way or the other. It was slightly more accurate than the stock barrel, but not more so than the Prometheus 6.03 or PDI 6.01 I tried.

 

The most accurate semiautomatic airsoft pistol I've seen had a TK Twist barrel, but the inner barrel was secured to a compensator mounted to the frame of the pistol as well, so it could have been that accurate with other barrels as well. Hmm.

 

-Sale

[shinhk]

You should be able to replicate that by increasing hop-up with a regular barrel.

What i meant was in theory if the "vortex cushion" works then the hop-up system is more effective in that after the nub hits the bb it doesn't touch anything else to affect the spin it has. With the idea that the bb is "bouncing" around in normal barrels AFTER it hits the nub then it might affect how the bb is spinning. It was just something i thought about after asking "how it COULD help" and why people are saying the distance is "better". This is all speculation of course. I'm not supporting the hop-twist, but i'm also not pushing it aside. I myself bought the hop twist because i like to try things on my own rather than take anyone's word/experience for it. It works as replacement for my stock barrel to give me better accuracy. Whether it creates a cushion or not, in my experience it ultimately serves it's purpose as a replacement for the stock one.

[Azulsky]

If you get a 6.01 tightbore and fat bb's ie excel/toytec, there isnt much room for the bb to "bounce" around the inside of the barrel to begin with. I dont see how having fancy grooves is any different than just having a bigger barrel to begin with, why doesnt the air just surround it then? I have never seen test results that prove these barrels to be anything more than hype.

 

LRB's work "better" because of the downward sloped barrel providing consistent hopup until the bb leaves it. Shame is they are usually tuned to a certain brand and weight of bb, and require a bv gun that lacks moving parts. The people who make them arent 100% on what specifications work best either, so the 300ft gun is feew and far between because its not an exact science.

 

 

[Stealthbomber]

What i meant was in theory if the "vortex cushion" works then the hop-up system is more effective in that after the nub hits the bb it doesn't touch anything else to affect the spin it has. With the idea that the bb is "bouncing" around in normal barrels AFTER it hits the nub then it might affect how the bb is spinning.

That doesn't work out though, does it?

 

If you have a BB of a specific weight then gravity is pulling it downward at a specific rate.

 

If 2 guns with no hop-up fire identical BBs out of the barrel at the same FPS then they should hit the ground at the same time regardless of what barrel they're shot from.

 

If you then add hop-up and try again there's only 2 things that can happen, logically.

1) The BB travels in a flat trajectory and travels a bit further.

2) The BB arcs up a bit and, as a result, travels even further still.

 

Again, the point is that if you have a gun firing at a given velocity, with a given weight of BB, it doesn't matter what sort of barrel or hop-up you have, if the BBs are flying through similar trajectories then they must be spinning in a similar manner.

 

Let's be arbitrary about it.

Let's say that Gun A is firing at 100m/sec and the hop-up makes the BB spin at 80 rps and flies horizontally.

That will generate a specific amount of lift and the BB will travel horizontally until drag causes the BB to slow down and it'll fall to the ground after about 60m.

 

With this in mind, the ONLY ways we can increase the range are to increase the power or increase the lift.

If you increase the power then a chrono would spot the change.

If you increase the lift then you'd think the BB would rise before dropping again.

 

For a TK barrel to operate as it claims to it, the hop up needs to exert the same (our 80 rps) spin on the BB, which is what's required to make it fly horizontally, and then, somehow, maintain that spin for a longer period.

It can't increase the spin cos that'd cause the BB to rise. It needs to apply the same spin but persuade the BB to maintain that lift for longer.

 

Like I say, the best evidence I've had of this was having somebody shooting at me with a TK G17 and, I admit, it DID genuinely seem to have more range than mine. I honestly couldn't say why, or why the improvement didn't seem to carry over to the SG1 barrel I also tried, but it's either something we're not understanding or something impossible to quantify.

[shinhk]

there isnt much room for the bb to "bounce" around

Okay i shouldn't say "bouncing" even though that's the term everyone seems to use here. The design is to avoid FRICTION that may cause a change in the way the bb is spinning.

 

I have never seen test results that prove these barrels to be anything more than hype.

And that's the reason why I bought one myself and tried it out. I don't believe in hype but I do believe what I see with my own eyes. Never heard of LRB's but aren't you doing the same thing as the people hyping out hop twists? Explaining how it can be "better" with an explanation of how it's supposed to work with no test results? Seems like you're "hyping" up LRB's to me.

[Delfi]

If you have a BB of a specific weight then gravity is pulling it downward at a specific rate.

 

yep ... a specific *constant* rate independent of its mass.

 

And using very basic physics a BB of one tonne and a BB of one gram, no matter how far they are fired, should have the same vertical drop time as oneanother.

 

Horizontal travel is another matter though.

 

 

D

 

(edit for clarity)

[Azulsky]

Okay i shouldn't say "bouncing" even though that's the term everyone seems to use here. The design is to avoid FRICTION that may cause a change in the way the bb is spinning.

 

 

And that's the reason why I bought one myself and tried it out. I don't believe in hype but I do believe what I see with my own eyes. Never heard of LRB's but aren't you doing the same thing as the people hyping out hop twists? Explaining how it can be "better" with an explanation of how it's supposed to work with no test results? Seems like you're "hyping" up LRB's to me.

 

Right but weve never seen any true tests of them(not that im not taking your word) like you said you have only ever tried the twist and not a 6.01 so we cant know for sure if its better. I would just like to see multiple barrels tried out using the same brand buckings, same brand nubs, and the same hopup on the same gun with the same weight and brand of bb's. Ive never seen a real analysis of the accuracy gains.

 

LRB's are pretty well documented, though i would say some people overstate their effective range because it becomes an issue of the bb taking time to get to target. I explained how it works, the bb rides along the top centerline of the barrel, i just said that perfect measurements dont exist and you arent going to get 2 just like each other in terms of performance, anyway that is for another time.

[mprojekt]

Right but weve never seen any true tests of them(not that im not taking your word) like you said you have only ever tried the twist and not a 6.01 so we cant know for sure if its better. I would just like to see multiple barrels tried out using the same brand buckings, same brand nubs, and the same hopup on the same gun with the same weight and brand of bb's. Ive never seen a real analysis of the accuracy gains.

 

LRB's are pretty well documented, though i would say some people overstate their effective range because it becomes an issue of the bb taking time to get to target. I explained how it works, the bb rides along the top centerline of the barrel, i just said that perfect measurements dont exist and you arent going to get 2 just like each other in terms of performance, anyway that is for another time.

 

I've heard of LRB's but I haven't had much luck tracking down a retailer that sells these. Please correct me if I am wrong - my undertanding of LRB's is that these are barrels designed to act as their own hop-up for the entire length of the barrel.

[Stealthbomber]

yep ... a specific *constant* rate independent of its mass.

 

And using very basic physics a BB of one tonne and a BB of one gram, no matter how far they are fired, should have the same vertical drop time as oneanother.

 

Horizontal travel is another matter though.

Eh?

 

Not really sure what you're driving at.

 

If you shoot a 1 tonne BB and a 1 gram BB out of the same gun they'll take the same length of time to hit the ground. The 1 gram BB will have traveled much further in a horizontal direction though.

 

And, given that the discussion is about range.....

[shinhk]

It can't increase the spin

I never said it would increase the spin. I'm saying there MIGHT be less friction that may affect the spin that the nub created originally. I'm bored at work so i'll try to explain the idea on how this system MIGHT work (i.e. not facts, just ideas).

 

Assuming no hop-up same length same inner diameter barrels are being used. If the pressure behind the barrel was the same PSI and a same weight bb was shooting out of both barrels the FPS will be the same if measured directly after the barrel. (usually this is how airsoft fps is measured...right after the barrel) Now if you add a hop-up to one of the barrels and did the same thing, the one with a hop up will have a small drop in fps because the bb touched something before it left the barrel. But as far as distance goes, one will travel further than the other because another force (lift) is acting upon the bb. This is the given PROVEN way on how the idea of hop-up works to give greater distance.

 

Now comes accuracy when using hop-up. Same two barrels with the same weight bb and hop-up will do the exact same thing. Make one barrel 2 inches and the other 10 inches (excluding any volumetric limits) the bb coming out of the longer barrel will obviously be more accurate because it has more time to regulate a "lined path" that's more straight. FPS will be different because the bb has more time to accelerate AND regulate a straight path out of the longer barrel than it does out of the smaller one (also PROVEN and the reason why snipers have longer inner barrels).

 

The japanese have always taken ideas and have tried to improve them. Making tightbores was the next step in getting more fps and more accuracy. With less air traveling around the bb and with a tighter pathway for the bb, it allowed the bb to be more affected by the pressure behind it and made it straighter and faster. So when people put in tightbores and chorno it yes...it shows that it's faster. That's an easy thing to prove.

 

This has been the norm for pretty much the lifetime of airsoft. Mr. Tanio Koba decided to try something different but i'm sure the idea of "rifling" the barrel didn't come to his mind first. The bb WILL touch the sides of the barrel maybe not bounce but there WILL be some sort of contact within the barrel. That's why if the barrel isn't clean and there's smudges inside it can greatly affect the trajectory of the bb. The idea isn't to make the bb's fly further, but to lessen the friction of the insides of the barrel. I'm pretty sure he didn't just rifle it in any old fasion and then sell it. Japanese take pride in their work to gain respect from other pride filled competitors in japan. (unlike the chinese who only care about money) The reason this barrel works on lower fps is probably becuase he tuned the groves to be at a lower fps since japan has stricter laws on how hard their airsoft can shoot. I'm sure the spacing in the groves have a meaning. I'm not sure why some people say it shoots further. Maybe it's the same reason why people say the AEP's shoot "far". When it's slow and straight you can watch the bb go the distance rather than going super fast and disappearing into the distance?

 

Whew...that took a good 20 min out of my work day! Though no one will probably read this haha!

[Delfi]

Eh?

 

Not really sure what you're driving at.

 

And, given that the discussion is about range.....

 

You said:

 

If you have a BB of a specific weight then gravity is pulling it downward at a specific rate.

 

No 'specific weight' comes in to this at all in terms of a downward 'pull' ... Also 'weight' is the wrong term to use.

 

Mass is irrelevant to any downward 'pull' too.

 

Gravity is nothing to do with the range of a BB ... only it's mass (not weight) and the vertical angle of the shot count for horizontal velocity and distance.

 

(assuming a simple vacuum based model that doesn't take all sorts of complications into account ... but accurate enough)

[Stealthbomber]

No 'specific weight' comes in to this at all in terms of a downward force ...

In context, I was making the point that, BBs of a similar weight, fired at a similar velocity, will travel a specific distance before falling to the ground, regardless of whether they're shot out of a TK barrel or a normal one.

 

Yes, in isolation, you're right and it was wrong to use the phrase "specific weight". What I should have said was "If you have a BB of a specific weight then gravity is pulling it downward as it travels a specific distance."

I guess you win the "trainspotter of the week award". Congratulations.

[Delfi]

In context, I was making the point that, BBs of a similar weight, fired at a similar velocity, will travel a specific distance before falling to the ground, regardless of whether they're shot out of a TK barrel or a normal one.

 

Yes, in isolation, you're right and it was wrong to use the phrase "specific weight". What I should have said was "If you have a BB of a specific weight then gravity is pulling it downward as it travels a specific distance."

I guess you win the "trainspotter of the week award". Congratulations.

 

Actually no, not in isolation.

 

The term is 'mass' not 'weight'. Weight is gravity related anyway. 'Similar' does not come into it at all.

 

Any mass is 'pulled' by gravity at exactly the same rate. The initial height and energy of the shot (assuming you're not shooting downwards in the direction of gravity) determines its time of flight.

 

The distance travelled is determined by muzzle kinetic energy ... the lighter the BB the faster it goes ... given a constant time of flight (see above) and constant muzzle energy a lighter BB will go further.

 

(that's assuming all kinds of stuff but is true in a vacuum)

 

'Trainspotter' or not, I'm right.

 

The effect (or not) of the barrel that's being discussed is a complex fluid dynamics issue and nothing to do with schoolroom Newtonian mechanics (with a sprinkling of Galileo).

 

Nominate your own award for inaccuracy and rudeness

[Sale]

Delfi, you're arguing besides the point and I don't think correcting small inaccuracies is necessary when you make assumptions yourself. All credit to pedantic people (I'm a nitpicker myself), but in the name of constructivity can you say whether you agree with the main point or not?

 

The point Stealthbomber and I were making is that two BBs of the same mass with velocity X and spin Y will travel exactly the same distance, regardless of the barrel that shot them.

 

LRB's work "better" because of the downward sloped barrel providing consistent hopup until the bb leaves it. Shame is they are usually tuned to a certain brand and weight of bb, and require a bv gun that lacks moving parts.

The italic part applies to this as well.

 

The downward slope itself doesn't add spin to the BB. Otherwise you'd get more hop-up simply by pointing a regular AEG a degree or two downwards. In an LRB, the BB jumps to the top of the barrel from the ramp in the beginning, and from there it's the air passing below the BB that keeps it in the top of the barrel. I do know that "the downward slope" is the popular theory, but it's a myth just like gear timing.

 

LRB's are great for the guns in which they are used, because a regular hop-up can not be applied. Hop-twist barrels improve the groupings so they are good barrels as well, but there's no "magic" in them that makes the BB float in the air for a longer time.

 

The BB has a velocity, direction and spin when it leaves the barrel. There's nothing else the barrel can do to it, whether it has grooves or an eccentric bore. There's lots of things you can do to make the velocity, direction and spin as consistent as possible. That will translate to improved groupings, but never increased total flight distance.

 

-Sale

[Delfi]

Delfi, you're arguing besides the point and I don't think correcting small inaccuracies is necessary when you make assumptions yourself. All credit to pedantic people (I'm a nitpicker myself), but in the name of constructivity can you say whether you agree with the main point or not?

 

Fair point Sale ... the OP's question is "are they worth it?"

 

Well, I have not tried one or even seen one in use as far as I know so any judgement I make is from reading around and also based on the opinion and experiences of others.

 

I can't see how they would work (that's not to say that they don't) but to me the pics of these look like rifling and surely you can't rifle a sphere.

 

Also, I don't understand the barrel wall/airflow explanation at all. I just can't see how, with a hop applied that a twisted inner would help. Surely a groove cut along the inner top in a straight line would make more sense for accuracy at least?

 

I'm wondering whether the reported 'flier BB's' are caused by a hopped BB bouncing (not rolling) on the upper side of the barrel and catching a groove at the wrong moment.

 

And besides, is any perceived minimal improvement actually worth the effort, risk and cost for a skirmishing weapon? Probably not.

 

There are much better and cheaper upgrades IMO.

 

D

[whosloosin92]

Also, I don't understand the barrel wall/airflow explanation at all. I just can't see how, with a hop applied that a twisted inner would help. Surely a groove cut along the inner top in a straight line would make more sense for accuracy at least?

 

The groove being cut on the top of the barrel is actually a design employed by Sheriff in an attempt to make a hop up effect. It did work but not quite as well as conventional LRB technology, if you could even call it that. I have personally owned an Asahi Bushmaster with a 20 inch LRB firing .3 gram bbs to 280 feet. I think it is important to note that there is a very difficult to explain phenomenon that occurs in some gas guns when using heavier weight bb's. The other posters stating that a bb moving x velocity and y spin will have the same as any other are absolutely correct. In cases such as LRB equipped gas guns the spin and velocity is most certainly not the same. The propulsion method is largely responsible for this because of how the expanding compressed gas will continue to accelerate the BB along the entire length of the barrel. When coupled with the LRB hop up providing spin all the way down the length of the barrel also you will get far different results than say an AEG providing a burst of air and hitting the hop up and having the chance to have that induced spin and velocity altered along the barrel.

 

I own a Tanio Koba barrel in my Tokyo Marui 1911 and I can safely say that there is no noticeable change in overall range. However I have consistently shot same hole groupings at 25 feet in a prone position with the pistol resting on the floor to keep it as steady as possible. I have tried the exact same pistol with all the exact same parts with other barrels and I was not able to observe the same performance as the Tanio Koba barrel.

[MarsdenH]

Weird, because when I dropped a TK twist barrel into my buddies stock AKSU (old gaurder kit, brand new TM hop-up unit, and mechbox) the gun got dramatically more range and accuracy.

 

Since then I've installed about 12 of them for locals and all seem to pick up more range then a 6.03 barrel.

[greg]

Put one in my sig 226, lost 20 fps, no noticeable improvement in accuracy. Mind you with 20 less fps there was no noticeable decrease inaccuracy either, so that could be seen as an improvement???

 

 

Greg.

[Sale]

The propulsion method is largely responsible for this because of how the expanding compressed gas will continue to accelerate the BB along the entire length of the barrel. When coupled with the LRB hop up providing spin all the way down the length of the barrel also you will get far different results than say an AEG providing a burst of air and hitting the hop up and having the chance to have that induced spin and velocity altered along the barrel.

But the velocity is measured after the BB leaves the barrel, and the amount of spin can be observed by looking at the flight path. If there's more spin, the BB curves up. If you get the right amount, it goes straight and then drops. There's nothing else to it.

 

A far more sensible theory to explain the long range observed with LRBs is that it shoots the BB downwards first, so more spin can be applied without having the BB curve up. But you could achieve the same effect by adjusting the sights on any airsoft gun.

 

The biggest improvement in accuracy in a Hi-Capa I've seen was from making the inner barrel steady. In other words, no matter how accurate your inner barrel is, it doesn't remove the play between the other parts. When the inaccuracy stems from a loose fit between the frame, slide and barrel; no inner barrel can fix that.

 

-Sale

[Glenn]

The distance travelled is determined by muzzle kinetic energy ... the lighter the BB the faster it goes ... given a constant time of flight (see above) and constant muzzle energy a lighter BB will go further.

 

 

Nominate your own award for inaccuracy and rudeness

 

 

Great post. If you're going to hand out awards for accuracy, make sure you're right first.

 

 

As has been BEAT TO DEATH on this forum, hundreds of times (is it still a sticky?), at the same muzzle energy, correct hop, etc, heavier BBs like to travel farther. They've got more momentum, they resists drag signifigantly better. God. Damnit.

 

 

Coming back to TK barrels...however well or not well they work for you...they're not making any kind of air cushion for the BB. Bernoulli effect, the reason hop up works, also means that the more air passing by the BB as it bounces along, the more it will want to bounce...not less.

[Sale]

Glenn, you snipped out his "backdoor" that it would be true in a vacuum.

 

Then again, in a vacuum an AEG wouldn't shoot the BB out at all...

 

-Sale

[Delfi]

Glenn, you snipped out his "backdoor" that it would be true in a vacuum.

 

Then again, in a vacuum an AEG wouldn't shoot the BB out at all...

 

-Sale

 

Now who's being pedantic? ... I qualified my 'backdoor' by stating that the whole thing is a complex fluid dynamics issue ...

 

The fact that it's an AEG is completely irrelevant. Using your own argument the BB has no memory of what fired it.

 

D

[Glenn]

Glenn, you snipped out his "backdoor" that it would be true in a vacuum.

 

Then again, in a vacuum an AEG wouldn't shoot the BB out at all...

 

-Sale

 

 

Ahhghghgg I guess you can't win them all